The invention relates to a process for mixing hydrocarbon feed and catalyst. A field of the invention may be the field of fluid catalytic cracking (FCC).
FCC is a hydrocarbon conversion process accomplished by contacting hydrocarbons in a fluidized reaction zone with a catalyst composed of finely divided particulate material. The reaction in catalytic cracking, as opposed to hydrocracking, is carried out in the absence of substantial added hydrogen or the consumption of hydrogen. As the cracking reaction proceeds substantial amounts of highly carbonaceous material referred to as coke are deposited on the catalyst to provide coked or carbonized catalyst. This carbonized catalyst is often referred to as spent catalyst. However, this term may be misconstrued because the carbonized catalyst still has significant catalytic activity. Vaporous products are separated from carbonized catalyst in a reactor vessel. Carbonized catalyst may be subjected to stripping over an inert gas such as steam to strip entrained hydrocarbonaceous gases from the carbonized catalyst. A high temperature regeneration with oxygen within a regeneration zone operation burns coke from the carbonized catalyst which may have been stripped.
FCC units are being designed increasingly larger because refiners are trying to capitalize on economies of scale. As the reactor riser of FCC units are designed with correspondingly increasing diameter, the distance between the wall mounted feed injectors and the axial center of the riser increases. As FCC reactor risers become larger, care must be taken to ensure hydrocarbon feed and catalyst are adequately contacted. Inadequate contact between catalyst and hydrocarbon feed can result in substantially higher dry gas and coke formation and reduced conversion of hydrocarbon feed, all undesirable performance attributes.
Improved apparatuses and processes are sought for the contacting of catalyst and hydrocarbon feed in larger FCC units.